Optical instrument.



e. SAEGMULLER. OPTICAL INSTRUMENT APPLICATION FILED FEB-1, 1910- I 93,473, Patented July 5, 1910.

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FIG: 6;

WITNESSES 5: v c& KW -9 fl/ e. N. SAEGMULLBR. OPTICAL INSTRUMENT.

APPLICATION FILED PEBJ, 1910.

. Patented July 5, 1910.

2 SHEETS-SHEET 2.

WITNESSES UNITED snares PATENT ornion.

GEORGE N. SAEGMULLER, OF ROCHESTER, NEW YORK, ASSIGNOR T0 BAUSCH & LOMBOPTICAL COMPANY, OF ROCHESTER, YORK, A CORPORATION OF NEW YORK.

OPTICAL INSTRUMENT.

Specification of Letters Patent.

Patented July 5, 1910.

Application filed February 1, 1910. Serial No. 541,275.

To all whom it may concern:

Be it known that I, GEORGE N. SAEGMUL- LER, a citizen of the UnitedStates, residing at Rochester, in the county of Monro-e and State of NewYork, have invented new and useful Improvements in Optical Instruments,of which the following is a specification.

In optical and other instruments of precision, particularly those whichare elongated or extended in their character and are subject to changesin temperature, a serious problem is presented in mounting the coactingparts, so that they will not be influenced by such changes and theiraccuracy consequently affected. For example in range finders, it is thecustom to mount the various optical elements within an inclosing tube ortubular casing constructed of steel or other metal. As there is apossibility that the tube under the influence of the suns rays willbecome bent or twisted to some extent, and this bending may influencethe support for the optical parts in a similar manner, the relation ofthe said optical parts may be altered so as to seriously affect theaccuracy of the instrument. While this variation will do no particularharm to certain elements of the instrument, the slightest relativechange, for instance, between the object glasses, which would throw themout of parallelism, would impair the accuracy of the whole instrument.

One of the primary objects of the present invention therefore is toprovide supporting means, which will eliminate the above defect ordanger, and in the accompanying drawings, is disclosed a structure,which has proven entirely successful.

In said drawings :Figure 1 is a plan view of substantially half of thesupport and Fig. 1 is a corresponding view of the other half, theinclosing casing being removed in order to avoid confusion. Figs. 2 and2 are side elevations of the same. Figs. 3, 4L and 5 are sectional viewsrespectively on the lines 3-3, 44: and 5-5 of Fig. 2. Fig. 6 is alongitudinal sectional view through another embodiment of the invention.Fig. 7 is a detail sectional view of a portion of the same on anenlarged scale. Fig. 8 is an end view.

Similar reference numerals designate corresponding parts in all thefigures of the drawings.

In the present embodiment disclosed in Figs. 1-5 inclusive, instead ofmounting the objective glasses, and in fact the whole central apparatusof the instrument on the long supporting base bar which carries thepenta prisms, these parts are carried on a separate supporting element,which may have quite a movement laterally on the bar, but to which it isconnected by tension rods that are under a very considerable strain. Forexample, the main base bar, designated 9, which is preferably providedwith a central longitudinal reinforcing flange 10, carries at its end,the usual penta prisms 11, and located on this bar between its ends, isa support 12 7 0 for the central instrumentalities, this supportcomprising a substantially flat saddle plate having oflset flanges 13that overhang and embrace the bar. Connected to the ends of said flangesare tension rods 14: having 7 convergently disposed outer ends 15 thatare clamped in split clips 16, which clips are secured to the flange 10of the base bar 9 by screws or other fasteners 17. In order to obtainthe necessary tension (about three hundred and fifty pounds), andmaintain the rods 14 in proper relation, spreader elements 18 areemployed that are interposed between the flange 10 of the base bar andsaid rods. The outer ends of these elements have seats 19 for thereception of the rods, and they are furthermore provided with.outstanding base cars 20, through which are passed adjusting screws 21that bear against the flange 10. The spreader elements furthermore havelongitudinal slots, through which are passed clamping screws 22.Furthermore in order that the said elements 18 can be properlypositioned with respect to the body of the bar 9, adjusting screws 23are passed through said elements and bear against the rear side of thebar. The saddle plate 12 is lightly spaced from the outer surface of thebar by means of bearing 1 heads 24 and the flanges 18 of said plate 102have adjusting screws 25.

It is the usual custom to construct the base bar 9 of a metal having acomparatively low co-eflicient of expansion, the metal usually employedbeing that known as Invar, and in the structure disclosed, the tensionrods 14: are formed of the same material. The central optical andmeasuring elements are carried by the central supporting saddle 12. Forinstance, the objectives are flecting prisms are designated 27, and theeye-piece is shown at 28. WVith this arrangement therefore, although thepenta prisms may change their relation, due to the warpingjof the bartheir optical performance will not be affected thereby and it is evidentthat this'will not affect the relation of the object glasses andthe-parts associated therewith. Consequently any variation of the basebarvwill not affect the accuracy of the instrument.

In Figs. 6, 7 and 8, another embodiment is disclosed. In this form, theelongated or extended base is a tubular support 29, the ends of whichareclosed by strong cap disks or plates 30 having openings 31therethrough. Tension rods 32 of Invar if the tube be Invar or othersuitable material extend longitudinally through the tubular snpport orbase and through the openings 31, and are placed under great tension.For

, example, if a tube of sixteen and one-half feet is employed, the rodsmay be placed under a tension of one thousand pounds each. Bearings forthe ends of the rods are employed that'are in the form of washers 33having knife edge bearings 34: on other washers 35 that abut against thecaps, and tension nuts 36 are threaded on the rods and bear against thewashers 33. Mounted on theserods at any point desired, are one or moresupporting saddles or elements 37, carrying the instrumentalities 38,such as the optical parts. It may also be desirable to apply spiralsprings at one end of the rods inorder to keep them under continuoustension.

From the foregoing, it is thought that the construction, operation andmany advantages of the herein described invention will .be apparent tothose skilled in the art, without further description, and it will beunderstood that various changes in the size, shape,

. proportion and minor details of construction,,may be resorted towithout departing from the spirit or sacrificing any of the advantagesof the invention.

Having thus fully described my invention, what I claim asnew, and desireto secure by Letters Patent, is p 1. In a structure of the character setforth, the combination with an elongated base member, of tension rodsconnected at their ends thereto, and an instrument-carrying deviceconnected to'the rods.

2. In a structure of the character set forth,

' the combination with a base, of tension rods placed under strain'andconnected at one of their two endsto the base, and a sup )ort connectedto the base by the tension r0 s.

3. In a structure of the character set forth, 1

the combination with an elongatedbase, of

instrument supporting means therewith and having oppositely extendingassociated tension members connected thereto and to the opposite endportions of the base, said tension members being placed iinder strain.

4:. In a structure of the character set forth, the combination with abase, of a supporting element associated therewith, and oppositelyextending tension elements connected to the supporting element and baseand placed under strain.

5. In a structure of the character set forth,

the combination with a base, of a supporting element mounted on thebase, oppositely extending tension rods connected to the element, andmeans connecting the outer ends of the rods to the base.

6. In a structure of the character set forth, the combination with anelongated base, of a supporting element of less length than the baselocated on the same between its ends, tension rods connected to thesupporting element and extending longitudinally of the base, and meansfor securlng the outer ends of the rods to the base.

7. In a structure of the character set forth, the combination with abase, of a supporting element, spaced tension rods connected to each endof the supporting element and to the base, and spreaders bearing againstthe rods between their ends.

8. In a structure of the character set forth, the combination with anextended base, of a saddle located on the base between its ends, tensionrods connected to each end of the saddle and to the base, and spreadersinterposed between the base and rods.

9. In a structure of the character set forth, the combination with aflanged base bar, of a saddle support located thereon, and tension rodsconnected to the ends of the saddle support and to the base bar beyondthe same.

10. In a structure of the character set forth, the combination with aflanged base bar, of a saddle support located thereon between its ends,and spaced tension rods connected to the ends of the saddle support andhaving convergent end portions connected to the base bar.

11. In a structure of the character set forth, the combination with aflanged base bar, of a saddle support located thereon between its ends,spaced tension rods connected to the ends of the saddle support andhaving convergent end portions connected to the base bar, and spacingelements interposed between the base bar and rods.

12. In a structure of the character set forth, the combination with aflanged base bar, of a saddle locatedthereon between its ends and havingdepending flanges that embrace the base bar, tension rods extendinglongitudinally of the base bar on opposite sides of the same andconnected to the ends of the saddle, means for securing said tensionrods to the base bar, spreaders interposed between the flange of thebase bar and the rods, Spreaders.

13. In a structure of the character set forth, the combination with abase, of a supporting member mounted thereon, tension rods connected tothe base and to the supporting member, and means engaging the tensionrods between their ends for placing said tension rods under strain.

14. In a structure of the character set forth, the combination with abase, of a supporting member mounted thereon, tension rods connected tothe base and to the supporting member, spreader elements engaging thetension rods between their ends, means for securing the spreaderelements to the base, and means for moving said spreader elementstransversely of the rods.

15. In a structure of the character set forth, the combination with anextended base, of a support associated with the base, instrumentsmounted on the support, and means for securing the base and supporttogether, said means permitting the movement of the base with respect tothe support, while maintaining said support and the instruments thereonin fixed relation.

16. In a structure of the character set forth, the combination with abase, of a supporting member associated therewith, op-

and means for adjusting said tical elements mounted on the base beyondthe supporting member, other coacting optical elements mounted on thesupporting member, and connections between the supporting member andbase, said member be ing placed under a strain that is disposedlongitudinally of the base.

17. In a structure of the character set forth, the combination ticalelements, and means for mounting the elements on the base, includingtension mem bers disposed longitudinally of and connected to the base,said members being placed under longitudinal strain.

18. In a structure of the character set forth, the combination with abase, of optical elements, and means for mounting the elements on thebase, including spaced tension rods disposed longitudinally of andhaving end portions connected to the base, said rods being placed underlongitudinal strain.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

GEORGE N. SAEGMULLER.

Witnesses:

HENRY C. THoN, DANIEL M. SMITH. 7.

with a base, of op-'

